SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '9a81cb6d91b1add43f54d5963f1f096d8cfbf5c04246c9db466792f1464cc546' 
  AND token = 'PQ6G4vu9S2cehzpgIJcutpF9f3z1wL8ubONMgf2+pmY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00027

JSON explain

{
  "query_block": {
    "select_id": 1,
    "message": "no matching row in const table"
  }
}